The present invention relates to an image processing apparatus for storing an image data read by scanning an original image in an image memory based on a scanning position corresponding to the image data. More particularly, the invention relates to an image processing apparatus capable of reading gradation image data or color image data, with a reduced memory costs.
In a conventional hand-scanner that reads an original image by a manual free scanning on an original, a scanning position of a read-sensor on an original is sequentially detected and, based on the detected scanning position, an image data is stored in an image memory.
In the detection of a scanning position, however, if used an auxiliary equipment, such as a sheet with a reference grid printed thereon, and a tablet, will increase the costs, and, if used an encoder which is attached to wheels moving integrally with the read-sensor and generates pulse signals according to the rotations of the wheels, will cause a great cumulative position errors due to machine accuracy, slipping of the wheels and the like.
Japanese Patent Application No. 7-080568 proposes an image processing apparatus that prevents image connection errors due to position errors of a scanning position, and reduces image distortion of a plane image connected in an image memory, by detecting position errors from an image data in an overlapping scanning area (in which an overlapping scanning is performed) and image information of a stored data, and then storing an image data in an image memory, based on a scanning position after correcting the detected position error.
This image processing apparatus, however, requires 4 M-bytes in reading gradation image data of 8-dot pixel when the storage capacity of the image memory is 8 pixels/mm, and it requires 12 M-bytes in reading color image data, thereby increasing the memory costs.
It is an object of the present invention to provide an image processing apparatus capable of reading gradation image data or color image data, with a reduced memory costs.
Other objects and advantages of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific embodiment are given by way of illustration only, since various changes and modifications within the scope of the invention will become apparent to the those skilled in the art from this detailed description.
According to one aspect of the invention, by connecting correction information storing means to an exterior computer, such as a personal computer, and then utilizing the personal computer as a second image storing means, it is possible that correction information is read from the correction information storing means and M value gradation image data is read from the second image storing means, to reproduce the read M value gradation image in a state where position errors at connection part has been corrected. In addition, since image data having N value smaller than M value is stored in a first image storing means that is required to be installed as an inner memory, it is possible to suppress the storage capacity of the first image storing means. As a result, the invention provides an image processing apparatus capable of reading gradation image with a reduced memory costs of storing means.
According to another aspect of the invention, since means for making N value performs binarization processing, it is possible to decrease storage capacity of a first image storing means as much as possible, thus enabling reduced storing means costs as much as possible.
According to another aspect of the invention, it is possible that correction information is read from the correction information storing means and a plurality of image data are read from the second image storing means, to reproduce the read color image in a state where position errors at connection part has been corrected. In addition, since N value smaller than M value image data is stored in a first image storing means that is required to be installed as an inner memory, it is possible to suppress the storage capacity of the first image storing means. As a result, the invention provides an image processing apparatus capable of reading color images with a reduced memory cost of storing means.
According to another aspect of the invention, it is possible to provide an image processing apparatus capable of reading color images without monochromating processing, thus leading to a reduced costs of storing means.
According to another aspect of the invention, it is possible to provide an image processing apparatus capable of reading red, green and blue image data, with a reduced storing means costs.
According to another aspect of the invention, it is possible to provide an image processing apparatus capable of reading colors, with a reduced manufacture steps of a line image sensor and a reduced manufacture costs.
According to another aspect of the invention, correction information may be stored at intervals of reading, thus simplifying a storage format for correction information storing means.
According to another aspect of the invention, even in color image, it is possible to obtain composite image in which position errors have been corrected by the same operation amount as in monochromatic image, thereby providing an image processing apparatus capable of reading colors with simplified circuits and a reduced manufacture costs.
According to another aspect of the invention, it is possible to decrease storing means capacity while suppressing visual deterioration of image quality, thereby providing an image processing apparatus capable of reading colors with a further reduced manufacture costs.
According to another aspect of the invention, it is possible to decrease operation amount for generating gradation image data and chromatic image data from color image data, thereby providing an image processing apparatus capable of reading colors with a still further reduced manufacture costs.
According to another aspect of the invention, a construction of storing means can be simplified.